Process of and apparatus for treating sheet materials and product



5 Sheets-Sheet 1 i W a w g) 3a v j K. M. FOX ETAL PROCESS OF AND APPARATUS FOR TREATING SHEET MATERIALS AND PRODUCT April 21, 1964 Filed July 31, 1959 FIGJS INVENTORS KARL M. FOX By RICHARD .w.scHurrE ATTORNEV ATING April 21, 1964 MQ/A X/ W FIG.2

Apnl 21, 1964 K. M. FOX ETAL 3,130,412

AAAAAAAAAAAAAAAAAAAAAAAAAAAAA NG SHE EEEEEEEEEEEEEEEEEE CT Fi 111111 11111 59 H6 6 FIG] United States Patent 3,139,412 PROCESS OF AND APPARATUS FOR TREATING SIHZET MATERIALS AND PRGDUCT Karl M. Fox, Swarthrnore, and Richard W. Sehntte, New

town Square, Pa., assignors to Scott Paper Company,

Chester, Pa., a corporation of Pennsylvania Filed July 31, 1959, Ser. No. 830,779 14 Claims. (Ci. 16113G) The present invention relates to the mechanical treatment of thin, planar bodies of deformable materials for modification of the physical characteristics thereof and more particularly to a new concept in the processing of paper webs.

Physical modification of sheet materials and especially paper involves well recognized procedures varying from the compacting and burnishing of smooth roll calendering, through pattern calendaring in which one of the rolls "carries a suitable design, simple embossing combining a patterned steel roll with a smooth roll or even mated patterned rolls, to the more rigorous treatment obtained through utilization of sim'darly patterned rolls carrying intermeshing surfaces. Although it may be acknowledged that these known procedures impart certain distinctive qualities to sheet materials, it is equally true that each has inherent limitations and the demand for an effective process to enhance the texture, softness, drape, flexibility, absorbency, bulk and decorative characteristics of deformable sheet materials remains unsatisfied.

It is a primary object of the present invention to provide an effective process of applying controlled mechanical forces to deformable sheet material for improvement of the physical characteristics thereof.

A further object of our invention is to provide a method of applying controlled mechanical forces to deformable sheet material to create therein a regularly disposed and sequentially repeated pattern of material distortion and distention.

Another object of this invention is to provide an improved apparatus for applying controlled mechanical forces to deformable sheet material.

A still further object of the invention is to provide a modified sheet material having improved physical characteristics.

Other objects and advantages of our invention will be readily apparent from the following detailed description of certain preferred embodiments thereof when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a perspective View of opposed rolls for the processing of deformable sheet materials as contemplated by our invention.

FIGURE 2 is a planar representation of the manner of intersection of the ribs of the opposed rolls of FIGURE 1.

FIGURE 3 is an enlarged fragmentary section taken substantially along the line 33 of FIGURE 2.

FIGURE 4 is an enlarged fragmentary section taken substantially along the line 44 of FIGURE 2.

FIGURE 5 is a fragmentary section taken substantially along the line 5-5 of FIGURE 1 and illustrative of a typical rib form constituting the surfaces of such rolls.

FIGURES 6, 7, 8 and 9 are also fragmentary sections of rolls illustrative of alternative rib forms which may be carried thereby.

FIGURES 10, 11, 12 and 13 are schematic elevations of opposed rolls illustrative of several embodiments of rib arrangements.

FIGURE 14 is a plan view of sheet material subjected to the treatment of the opposed rolls of FIGURE 1 and illustrative of the deformation obtained therein.

FIGURE 15 is an enlarged fragmentary sectional view taken along the line 15-45 of FIGURE 14.

3,130,412 Patented Apr. 21, 1964 FIGURE 16 is an enlarged fragmentary sectional View taken along the line l6l6 of FIGURE 14; and

FIGURE 17 is an enlarged fragmentary sectional view taken substantially along the line l7l7 of FIGURE 14.

Briefly stated the present invention contemplates a new commercial product as well as its production by the application of controlled mechanical forces to a deformable sheet material during its passage between a pair of opposed rolls carrying upon their surfaces a plurality of resilient ribs so disposed as to intersect at the tangential nip of the rolls, whereby there is created in said sheet a regularly disposed and sequentially repeated pattern of material distortion and distention.

Referring to the drawings, a sheet 1 of deformable material, for example, paper, plastic or metal foil, is given modified physical properties by its passage between a pair of opposed rolls 2 and 3, provided with shafts 4 and 5 projecting outwardly therefrom and through which they may be mounted in suitable apparatus (not shown) providing means for their rotation, as well as pressure loadings if desired, such mounting and drive apparatus being well known to the art and needing no detailed explanation for an understanding of the immediate invention.

The rolls 2 and 3 carry ribs of a resilient material, such as rubber or plastic, which may be selected as to thick ness and hardness as determined by the nature of the material in the sheet 1 undergoing processing and the end effect desired.

As shown in FIGURE 1, the rolls are provided with a pattern comprising a plurality of regularly spaced peripheral ribs 7 and 8 preferably disposed helically along the entire length of each roll. The rib contour or transverse section which is to a large degree important in determining the characteristics of the pattern effected in the sheet material 1, may be altered as desired. Several contours are illustrated in FIGURES 5-9 of the drawings. In general, it is contemplated that the ribs 7 and 8 will be of V-shape in cross section with either a sharp, rounded or flattened apex, again as determined by the nature of the material being processed and the end effect desired. The pitch or number of ribs per inch of roll surface may also be varied as desired and will in turn determine the fineness of the pattern in and the degree of change in physical characteristics of the material.

In a preferred embodiment of the invention, the helix angle of the ribs 7 and 8 determines the angle of intersection of such ribs at the roll nip 9 as best seen in FIG- URE 1 and the modified arrangements thereof illustrated in FIGURES 10, 11 and 13. It should be realized, however, that a helical arrangement of ribs is not essential to their intersection at the roll nip and an angular relationship of ribs as shown in FIGURE 12 will enable attainment of the desired processing of deformable sheet material.

As the sheet material 1 passes between the rolls 2 and 3, a sequential material distortion is efiected beginning at the first point of contact 10 between the intersecting resilient ribs 7 and 8 as best seen in FIGURE 3. This initial contact constitutes a point of fixation for the sheet material about which there is compression and deformation of such sheet material during passage through the nip of the rolls, this action reaching a maximum at the center line 11 of the nip 9. This material deformation is produced as the result of forces arising from rib interference and sufficient space 18 provided between the ribs to permit lateral displacement therein, as shown in FIG- URE 4. It is believed that as the contacting ribs 7 and 8 advance the sheet 1, there is a gripping force exerted against the sheet, such forces increasing as the ribs per se are deformed under pressure, and there is established a vector of deformation in a plane parallel to the plane of the sheet material 1 which will cause, under most conditions, a twisting deformation about each point of fixation. The existence and magnitude of the twisting deformation is related to the angle of intersection of these ribs. As the sheet material emerges from the nip 9, the rib interference diminishes and there remains in the sheet material a permanent pattern of deformation and distortion.

The sheet material 1, following treatment, has formed therein a pattern of ridges and valleys designated generally by the lines 25 and 25 respectively in FIGURE 14. The ridges 25 of one face of the sheet material constitute the valleys 26 in the opposite face thereof and the ridges and valleys intersect at points of fixation 27 as seen in FIGURES 14, 15 and 16. Patterns differing from that shown in FIGURE 14 are possible from different rib configurations and operating conditions.

The rolls 2 and 3 shouid preferably operate at substantially equivalent peripheral speeds during material processing in order that the resultant material pattern will be of desirable character. The nip pressure petween the rolls may be varied, as has been indicated hereinbefore, in accordance with the nature of the material being processed and the end result which is desired.

-While, for simplicity of roll fabrication, identical rib patterns may be preferred, it is not intended that the present invention shall be restricted thereto. Other angular rib arrangements are entirely practicable and, in fact, as illustrated in FIGURE 12, one roll may carry a series of spaced longitudinal ribs while the second roll has spaced annular ribs.

The principles of our invention may be illustrated by the following examples.

Example I essing is given in the following table.

Before After Bulk 1 180. 5 Tensile (Machine Direction) 17.0 Tensile (Cross Directin)---. 6.1 Him (1 feel Excellent 1 Thickness of 24 sheets under aloading of 235 grams per square inch expressed in thousandths of an inch.

Example 11 The procedure of Example I was repeated with a twoply facial tissue having a basis Weight of 10.2 pounds per ream (2880 square feet) being passed through a nip operated under a pressure loading of 34 pounds per linear inch. The physical properties of the paper before and after processing are listed hereinafter.

Before After Bulk 73. 81.8 Tensile (Machine Direction)-. oz.- 15. 5 14. 9 Tensile (Cross Direction) oz 5. 8 5. 1 Handfeel Good Excellent 1 Thickness of 24 sheets under a loading of 235 grams per square inch ex pressed in thousandths of an inch.

Example III The procedure of Example I was again followed using a heavy kraft paper having a basis weight of 49 pounds per ream 2880 square feet) and approximately moisture content. To obtain a satisfactory mechanical action upon this heavier paper, the nip pressure loading was increased to 55 pounds per linear inch and rubber having a Shore A durometer reading was employed in the roll coverings.

The physical properties of the paper before and after processing are given in the following table.

Before After Caliper ..inches.. 0. 0055 0. 0191 Tensile (Machine Direction). ..pounds.- 29.4 27.2 Tensile (Cross Direction) --do-- 19.8 15.4 Stretch (Machine Direction)- .-percent.- 3.3 9.4 Stretch (Cross Direction) .-do 4.5 5.0

Example IV Aluminum foil having a basis weight of 29.5 pounds per ream (2880 square feet) waspressed between op pressed rolls as in Example I with a pressure loading at the nip of 11 pounds per linear inch. The results of this processing are given in the following table.

A composite sheet of aluminum foil and paper adhesively united and having a basis weight of 31 pounds per ream (2880 square feet) was processed as in Example ".HI except that the pressure loading of the nip was reduced to 5 pounds per linear inch. The results obtained are set out hereinafter.

Before After Caliper --inches-- 0. 0025 0.0090 Tensile (Machine Direction)- pounds 11.9 11.8 Tensile (Cross Direction)-...' .-do-.-- 9. 3 9.0 Stretch (Machine Direction). percent-- 2.2 2.9 Stretch (Cross Direction) 0---- 2.6 2.3

The foregoing examples demonstrate clearly the improved characteristics imparted to sheet materials by our invention. Paper towel stock will acquire improved softness, drape and an increased water absorbency with no material diminution of its original strength. Toilet tissues are given greater bulk and enhanced esthetic appearance and textures. The physical appearance of metallic foils and foil laminates can also be improved. By variation in the hardness of the patterned roll covers and nip pressures the present process can be utilized to alter the physical characteristics of even more dense. sheet materials, such as board stock and the like, it being necessary only that the material possess sufiicient plasticity to effect deformation.

It will be readily apparent that various modifications in the arrangement of component parts and the operating conditions imposed thereon are possible wtihout departing from the spirit of the invention or the scope of the ap pended claims.

.What we claim is:

1. In combination in apparatus for modifying the physical characteristics of deformable sheet material, a pair of opposed rolls carrying upon their surfaces ribs of resilient material, the ribs of each roll being so disposed as to intersect with the ribs of the opposite roll in the nip between said rolls, the disposition of said rolls being such that intersecting apex regions only of said ribs are deformed as the rolls are turned with a sheet of material therebetween.

2. In combination in apparatus for modifying the physical characteristics of deformable sheet material,'a pair of opposed rolls carrying upon their surfaces ribs of resilient material, said ribs being helically disposed so as to intersect in the nip between said rolls, the disposition of said rolls being such that intersecting apex regions only of said ribs are deformed as the rolls are turned with a sheet of material therebetween.

3. In combination in apparatus for modifying the physical characteristiw of deformable sheet material, a pair of opposed identical rolls carrying upon their surfaces ribs of resilient material, said ribs being helically disposed so as to intersect in the nip between said rolls, the disposition of said rolls being such that intersecting apex regions only of said ribs are deformed as the rolls are turned with a sheet of material therebetween.

4. In combination in apparatus for modifying the physical characteristics of a paper web, a pair of opposed identical rolls carrying upon their surfaces ribs of resilient material, said ribs having sloped sides and being helically disposed so as to intersect in the nip between said rolls, the disposition of said rolls being such that intersecting apex regions only of said ribs are deformed as the rolls are turned with a paper web therebetween.

5. Sheet material having valleys and ridges formed therein, the valleys on one side of the material constituting the ridges on the other side, and having valley and ridge intersections where are present a planar deformation of the sheet material.

6. Sheet material having valleys and ridges formed therein, the valleys on one side of the material constituting the ridges on the other side, and having valley and ridge intersections where are present a planar twisting deformation of the sheet material.

7. Sheet material having a plurality of regularly spaced valleys and ridges formed therein, the valleys on one side of the material constituting the ridges on the other side, and having periodic valley and ridge intersections where are present a planar deformation of the sheet material.

8. Sheet material having a plurality of regularly spaced valleys and ridges formed therein, the valleys on one side of the material constituting the ridges on the other side, and having periodic valley and ridge intersections where are present a planar twisting deformation of the sheet material.

9. Paper having a plurality of regularly spaced valleys and ridges formed therein, the valleys on one side of the paper constituting the ridges on the other side thereof,

and having periodic valley and ridge intersections where are present a planar deformation of the paper.

10. Paper having a plurality of regularly spaced valleys and ridges formed therein, the valleys on one side of the paper constituting the ridges on the other side thereof, and having periodic valley and ridge intersections where are present a planar twisting deformation of the paper.

11. Paper having a plurality of regularly spaced valleys and ridges formed therein and extending throughout its area, the valleys on one side of the paper constituting the ridges on the other side thereof, and having a regularly disposed pattern of valley and ridge intersections where are present a planar twisting deformation of the paper.

12. A process of modifying the physical characteristics of a paper web which comprises establishing a nip between a pair of rolls having resilient ribs thereon, the ribs on one roll intersecting the ribs on the other roll in said nip, disposing the web in said nip, rotating said rolls to continuously advance the web through said nip and to grip said Web between intersecting apex regions of said ribs, the compression of said intersecting apex regions of said ribs effecting deformation of the gripped areas of said web.

13. A process of modifying the physical characteristics of deformable sheet material which comprises disposing a sheet of said material between opposed members having resilient ribs thereon, the ribs on one member intersecting at spaced locations with the ribs on the other member and moving the ribs of one member relative to the ribs of the other member to grip said sheet between intersecting regions of said ribs and effect deformation of said sheet generally in a plane parallel to the plane of the sheet in the gripped regions of the sheet.

14. The process of claim 13 in which the deformable sheet material is paper.

References Cited in the file of this patent UNITED STATES PATENTS 673,041 Ault Apr. 30, 1901 969,460 Chartener Sept. 6, 1910 2,257,429 Ruegenberg Sept. 30, 1941 2,290,608 Evans July 21, 1942 2,834,809 Schutte et a1 May 13, 1958 2,958,608 Barnard Nov. 1, 1960 

11. PAPER HAVING A PLURALITY OF REGULARLY SPACED VALLEYS AND RIDGES FROMED THEREIN AND EXTENDING THROUGHOUT ITS AREA, THE VALLEYS ON ONE SIDE OF THE PAPER CONSTITUTING THE RIDGES ON THE OTHER SIDE THEREOF, AND HAVING A REGU- 